ORGANIC MOVEMENTS 111 



remembering in the psychological sense, is constituted by 

 the mere act of association by contiguity : a stimulus not 

 only recalls the idea of sameness but also recalls other 

 stimuli (and effects) which had been combined with it the 

 first time. Memory of this sort, of course, is only concerned 

 in acting, but is not acting ; it even is better kept sepa- 

 rate from true "experience' 1 altogether, the word "experi- 

 ence ' being reserved for something about acting as an 

 actuality. 



" Experience " in this sense is seen in its most simple 

 type, if one of the elements concerned in associative memory 

 is a certain behaviour of the motor organs, able to call forth 

 liking or to overcome disliking. It is from this kind of 

 experience that the acting of man takes its origin, as we 

 have discussed already, when dealing with the so-called 

 origin of the act of volition ; but it is this kind of 

 experience, too, which fully deserves the name of a basis of 

 " acting," even if almost no resolution of the given 

 "historical basis of reacting' 1 into its remoter elements 

 occurs. 



American authors l especially have studied the most 

 simple types of acting in lower animals, in particular in 

 Infusoria, Actiniae, worms, and crayfishes. We have stated 

 on another occasion already, when trying to define the 

 concept of acting in its contrast to other kinds of changeable 

 motor reactions, that a mere consecutive line of changes of 

 reactions in response to one and the same often repeated 

 stimulus, as discovered by Jennings in the Protozoon 

 Stentor and in the earthworm, never deserves the name of 

 real acting, but may be due either to fatigue or to some 



1 For literature see the work of Jennings referred to at page 17, note 1. 



